Phonograph



G. B. BURCH.

PHONOGRAPH.

APPLICATION FILED SEPT. 15, 1919.

Patehted May 2, 1922.

2 SHEETS-SHEET 1.

nu l- 11' INVENTOR .4; ATTORNEY G. B. BURCH.

PHONOGRAPH. APPLICATION FILED SEPT. 15, 1919.

1,414,802. Patented May 2, 1922.

2 SHEETS-SHEET 2.

L; ATTORNEY v umrrso STATES- PATENT OFFICE.

(more: a. sums, or NEW Yoax, N. 2.,

ASSIGNOB TO LESLIE STEVENS, OF GLEN amen, NEW JERSEY.

rnoivoemrr.

1,414,802, Specification of Letters Patent.

Application filed September 15, 1919. Serial No. 323,687.

To all whom it may concern:

Be it known that I, GEORGE B. BURCH, a citizen of the United States, residin at New York city, in the county of New ork and State of New York, have invented certain new and useful Improvements in Phonographs, fully described and represented in the following specification and the accompanying drawing, forming a part of the same.

This invention has been m'ade especially with the idea of providing an improved phonograph reproducer of the class having a large direct-acting diaphragm by WhlCh sound waves are set up directly in the surrounding atmosphere without requiring any horn or other amplifying device: and the invention aims to provide an improved device of this class which shall be highly sensitive and responsive to sound vlbrations,

and which when used as a phonograph reproducer shall operate to reproduce sounds recorded on a phonograph record very perfectly as to quality and in the desired volume. The invention is not limited to instruments or devices for use in reproducing sound through the mediation of a record such as the usual phonograph record,- but may obviously be applied to. other uses'in sound reproduction and recording.

An understanding of the invention can best be given by a description of an embodiment of all the features of the invention, and such a description will now be given inconnection with'the accompanying drawin s, and the invention will then be particu arly pointed out in the claims. In said drawings v Figure 1 is a sectional view of a phonograph provided with a reproducer embody- 1ng my invention; and

igure 2 is a partial sectional view taken at right angles to Fig. 1 and showing the stylus-holder and transmission rod and portions of the diaphragms.

Figure 3is a face view of the lower diaphragm. The drawings show a phonograph 1 having a suitable casing 2 in which is mounted the usual motor 3 which is provided with the usual spindle 4 on which. is mounted a turntable 5 in the customary manner. This turn-table 5 is adapted to support a disk record 6 of the usual kind. At one side of the turn-table 5 is mounted a bracket 7 on the thin sheet celluloid of .01 inch thickness,

cloth, or textile fabric, reinforced at its center by a layer 11, the cloth being treated with a suitable stiffening material to give the diaphragm the necessary resiliency, and also paper. As showing a way of treating cloth with a stiffening material to 've the necessary resiliency U. S. Patent 0. 488,190 may be mentioned. It isa large direct-acting diaphragm reguiring no amplifying horn, that is, it is o a size to produce sounds of the desired volume by setting up sound waves directly in the surrounding atmosphere. I have found a size of from nine inches to a foot in diameter most desirable. This upper or main diaphragm should best be of outwardly bulging form, and it is most desirably of convex conoidal form, as shown, curving convexly from the center outward toward its edge in all radial directions, as described more particularly and as claimed broadly in my co-pending application Serial No. 323,688, filed September 15, 1919, and it has a cylindrical flange which fits a corresponding flange of the lower diaphragm 13, which serves as a supportfor the upper diaphragm. Adjacent its peripheral flange, the upper diaphragm is desirably formed with a circumferentially extending undulation or reversed curve forming a gutter or trough arid may be provided with perforations 12 at its guttered portion near its periphery. The lower diaphragm 13 is most desirably of concave conoidal form, curving concavely from a central neck outward toward toward its edge, and has an opening at its center, that is, at the end of its neck in the form shown, so as to permit the needle-, or stylus-holder 14 to move freely therein without touching the diaphragm. This lower diaphragm may be of the same material as the upper dlaphragm, but is most Patented May 2, 1922.

2 reissue and hay' its upper end held between are parts split screw plug 111, being secured to 1/ parts of such plur 5 ut. r hold the plate firmly between them as by screws as shown.

T he plug 17 seats in a tip piece 18 which extends through the neck of the lower phragm 13 and is secured. thereto by a. clamping collar 19 which screws onto tip piece and extends upward outside the neck. The stylus holder has its upper end a lug 2O projecting away from the plane of the plate 16, and to this lug is connected the lower end of a transmission rod 21 as by having its threaded end screwed into threaded opening in the lug. The rod passes freely through an opening in the plug 1? and extends upward to the center of the diaphragm. The lower end of the transmission rod is thus connected to the stylus holder at a point adjacent to but laterally offset from the axis of oscillation of the holder. The upper end of the transmission rod is secured to the diaphragm 10, as by means of damp ing collars or nuts on the threaded end of the rod, as shown, so that all vibrations received by the stylus from the record 6 are transmitted through the stylus-holder 14; and transmission rod 21 to the diaphragm. The diaphragm being thus caused to vibrate sets up the desired sound waves directly in the surrounding atmosphere without requiring the aid of any amplifying horn. Because of the relatively great length and slenderness and resulting flexibility of the transmission rod, the vibrations of the stylus holder imparted to the rod through the lug 18 are transmitted to the diaphragm in the direction of the length of the rod. By using a flexible rod and connecting it rigidly to the stylus holder and diaphragm, the possibility of lost motion due to pivot pin connections is avoided. Furthermore, in the construction shown, in which the supporting means for the diaphragm 10 is in the form of a second diaphragm, the stylus-holder 14: and its connected parts including the trans mission rod 21, acting oppositely and simultaneously on the two diaphragms, cause the two diaphragms 10 and 13 to vibrate in unison, so that when the instrument is played the two diaphragms act harmoniously to reinforce each other in producing sounds of the desired volume and which will be a very perfect reproduction of the sounds recorded in the record.

shown in Fig. 1, the diaphragm seructure is adapted for re reducing from records having latera out grooves. To reproduce from vertical y out, hill'and dale records, it is obviously only necessary to turn the diaphragm structure 90 degrees about its axis so as to bring the pivotal axis of the-stylus-holder parallel to the surface of the record.

llhile have shown and described one embodiment of my invention, it is obvious that the invention is not restricted thereto but is broad enough to cover all structures that come within the scope of the annexed claims.

What is claimed is:

1. A. device of the class described, comprising two diaphragms with connected flanges, a stylus-holder pivotally mounted in one diaphragm, and a transmission. rod connected to the stylus-holder and tothe other diaphragm.

2. A device ofthe class described, com prising two peripherally connected and centrally spaced diaphragms, a stylus-holder carried by one of said diaphragms and capable of vibratory oscillation, and a transmission connection extending from the stylus-holder to the other diaphragm, whereby vibrations are transmitted directly from the stylus-holder to said other diaphragm in the direction of the length of said connection.

3. A device of the class described, comprising a main sound reproducing diaphragm, a second diaphra m peripherally connected to the main diap ragm, a stylusholder carried by the second diaphragm, and a longitudinally vibratory member connecting the stylus-holder with the main diaphragm for the direct transmission of the vibrations.

4. A device of the class described, comprising a main sound reproducing diaphragm, a second diaphragm peripherally connected to the main diaphragm, a rigid stylus-holder carried by ithe second dia- .phragm mounted to be capable of vibratory oscillation under the influence of a record, and a flexible transmission rod extending from the stylus-holder to the main diaphragm and rigidly connected to both the stylus-holder and the main diaphragm,

whereby vibrations are transmitted directly' from the stylus-holder to the main diaphragm in the direction of the length of said connection.

5. A device of the class described, comprising a main sound reproducing diaphragm of a size to produce sounds of the desired volume by setting up sound waves directly in the surrounding atmosphere, at second diaphragm peripherally connected to the main diaphragm, a stylus-holder carried by the second diaphragm, and a transmission connection extending from the stylusholder to the main diaphragm, whereby vibrations are transmitted directly from the stylus-holder to the main diaphragm in the direction of the length of said connection, said diaphragmshavlng their centers spaced apart, and said connection being of light weight and non-extensible under the strain to which it is subjected.

6. A device of the class described, comprising a main sound reproducin diaphragm of outwardlybulging form and of a size to produce sounds of the desired volume by setting up sound Waves directly in the surrounding atmosphere, a second diaphragm peripherally connected to the main diaphragm, a stylus-holder carried by the second diaphragm, and a transmission connection extending from the stylus-holder to the main diaphragm whereby vibrations are transmitted directly from thestylus-holder to the main diaphragm in the direction of the length of said connection.

7. A device of the class described, comprising a main sound reproducing diaphragm of outwardly bulging form and of a size to produce sounds of the desired volume by setting up sound waves directly in the surrounding atmosphere, a second diaphragm which curves outwardly from its outer portion to a central neck, said diaphragms being formed with peripheral flanges by which they are connected together,\

a stylus-holder mounted in the neck of the second diaphragm to be capable of vibratory oscillation under the influence of a record, and a transmission connection extending from the stylus-holder to the main diaphragm, whereby vibrations are transmitted directly from the stylus-holder to the main diaphragm in the direction of the length of said connection.

8, A device of the class described, comprising a main sound reproducing diaphragm of conoidal form convexly curved from its center radially outward and of a size to produce sounds of the desired volume by setting up sound waves directly in the surrounding atmosphere, a second diaphragm peripherally connected to the main diaphragm, a stylus-holder carried by the second diaphragm, and a transmission connection extending from the stylus-holder to the main diaphragm.

9. A device of the class described, comprising a main sound reproducing diaphragm of outwardly bulging form and of a size to produce sounds of the desired volume by setting up sound waves directly in the surrounding atmosphere, a second diaphragm peripherally connected to the main diaphragm and formed with a plurality of sound openings ranged about its central portion, a stylus-holder carried by the second diaphragm, and a transmission connection extending from the stylus-holder to the main diaphragm.

10. A device of the class described, comprising a main sound reproducing diaphragm of outwardly bulging form and of a size to produce sounds of the desired volume by setting up sound waves directly in the surrounding atmosphere, a second diaphragm peripherally connected to the main diaphragm, said diaphragms being formed with overlapping peripheral flanges, a stylus-holder carried by the second diaphragm, a transmission connection extending from the stylus-holder to the main diaphragm, and a swivel support connected to the peripheral flange of one of the diaphragms and formed to permit the diaphragms to swing laterally and vertically in an inclined positlon.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

GEORGE B. BURCH. 

